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NEWCASTLE DISEASE 
Aetiology Epidemiology Diagnosis Prevention and Control References 
AETIOLOGY 
Classification of the causative agent 
Newcastle disease (ND) is a member of the family Paramyxoviridae in the genus Avulavirus. There are ten 
serotypes of avian paramyxoviruses designated APMV-I to APMV-10 and ND virus (NDV) has been 
designated APMV-1. NDV has also been categorised into five pathotypes based on clinical signs in 
infected chickens, designated: a) viscerotropic velogenic, b) neurotropic velogenic, c) mesogenic, 
d) lentogenic or respiratory and e) aymptomatic. Pathotype groupings are rarely clear-cut. 
Temperature: Inactivated by 56°C/3 hours or 60°C/30 minutes. 
pH: Inactivated by acid pH ≤ 2. 
Chemicals/Disinfectants: Ether sensitive; inactivated by formalin, phenolics and oxidising agents (e.g. 
Virkon®); chlorhexidine, sodium hypochlorite (6%). 
Survival: Survives for long periods at ambient temperature, especially in faeces. 
EPIDEMIOLOGY 
Hosts 
 Many species of birds both domestic and wild 
o Chickens are highly susceptible to disease; turkeys do not tend to develop severe signs 
o Game birds (pheasants, partridges, quail and guinea fowl) and parrots (order 
Psittaciformes) vary in susceptibility; cockatiels are susceptible 
o Wild birds and waterfowl (order Anseriformes) may harbour virus subclinically; some 
isolates within certain genotypes have caused epiornitics within these species 
o Young cormorants (Phalacrocorax spp.) have demonstrated disease associated with 
APMV-1 
o Disease has been recorded in ostriches (order Struthioniformes) and pigeons (order 
Columbiformes) are known to be susceptible 
o Raptors are usually resistant to ND; except reports of acute disease in bearded vulture 
(Gypaetus barbatus), white-tailed sea eagle (Haliaeetus albicilla), a wild osprey (Pandion 
haliaetus) and some species of falcons 
o Other birds known to have been affected by NDV include: gulls (order Charadriiformes), 
owls (order Strigiformes), and pelicans (order Pelecaniformes). 
o Passerine birds (order Passeriformes) are variable in their susceptibility; some species 
show no signs of disease but excrete NDV while others may develop severe disease 
o Reports of deaths in crows and ravens (genus Corvus) have been recorded 
o Acute ND has been recorded in penguins (order Sphenisciformes) 
 The morbidity and mortality rates vary among species, and with the strain of virus 
 Humans may become infected; manifested by unilateral or bilateral reddening, excessive 
lachrymation, oedema of the eyelids, conjunctivitis and sub-conjunctival haemorrhage 
Transmission 
 Direct contact with secretions of infected birds; principally via ingestion (faecal/oral route) and 
inhalation 
 Fomites: feed, water, implements, premises, human clothing, boots, sacks, egg trays/crates, etc. 
o Survival of agent is prolonged by presence of faeces; as in soiled egg shells 
 Hatching chicks may be infected through egg for some NDV strains; transmission of highly 
virulent isolates is uncommon 
 No clear evidence of role of flies in mechanical transmission 
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Sources of virus 
 Respiratory secretions/discharges and faeces of infected birds 
 All parts of the carcass 
 Virus is shed during the incubation period, during clinical stages and for a limited period during 
convalescence 
 Wild birds and waterfowl may act as reservoir hosts for lentogenic pathotypes of ND; 
subsequently, these viruses could become virulent following mutation upon establishment in 
domestic poultry 
 Some psittacine birds have been demonstrated to shed ND virus intermittently for over 1 year and 
been associated with introduction into poultry 
Occurrence 
Velogenic NDV is endemic in areas of Mexico, Central and South America, widely spread in Asia, the 
Middle East and Africa, and in double-crested wild cormorants in the US and Canada. Lentogenic strains 
of NDV are worldwide in their distribution while widespread mesogenic pathotypes with a special 
adaptation to pigeons (i.e. pigeon paramyxovirus) do not appear to infect other poultry readily. 
For more recent, detailed information on the occurrence of this disease worldwide, see the OIE 
World Animal Health Information Database (WAHID) interface 
[http://www.oie.int/wahis/public.php?page=home] or refer to the latest issues of the World Animal 
Health and the OIE Bulletin. 
DIAGNOSIS 
Incubation period is 2–15 days with an average of 5–6 days; some species may be over 20 days. For the 
purposes of the OIE Terrestrial Animal Health Code, the incubation period for ND is 21 days. 
Clinical diagnosis 
Clinical signs seen in birds infected with NDV vary widely and are dependent on factors such as: the 
virus/pathotype, host species, age of host, co-infection with other organisms, environmental stress and 
immune status. Clinical signs alone do not present a reliable basis for diagnosis of ND. Morbidity and 
mortality depend on virulence of the virus strain, degree of vaccinal immunity, environmental conditions, 
and condition of the flock. 
Lentogenic strains 
 Usually associated with subclinical disease marked by mild respiratory disease; coughing, 
gasping, sneezing and rales 
 If other co-infectious agents circulating, can result in severe signs 
 Mortality is negligible 
Mesogenic strains 
 May produce cause acute respiratory disease and neurologic signs in some species 
 Mortality rate is usually low (cases may present pulmonary oedema and pancreatic necrosis 
Differential diagnosis 
 Fowl cholera 
 Highly pathogenic avian influenza 
 Laryngotracheitis 
 Fowl pox (diphtheritic form) 
 Psittacosis (psittacine birds) 
 Mycoplasmosis 
 Infectious bronchitis 
 Aspergillosis 
 Also management errors such as deprivation of water, lack of or nutritionally deficient feed and 
poor ventilation 
 In pet birds: Pacheco's parrot disease (psittacine birds), salmonellosis, adenovirus, and other 
paramyxoviruses 
 In cormorants and other wild waterfowl: botulism, fowl cholera and conformational abnormalities 
Laboratory diagnosis 
Any laboratory processing samples or undertaking diagnosis from samples should meet the requirements 
for the appropriate Containment Group as determined by the risk assessment and as outlined in Chapter 
1.1.2 Biosafety and biosecurity in the veterinary microbiology laboratory and animal facilities. Countries 
lacking access to such a specialised national or regional laboratory should send specimens to an OIE 
Reference Laboratory. 
Samples 
Samples should be collected from recently dead birds or moribund birds that have been killed humanely. 
 
Identification of the agent 
 Dead birds: oro-nasal swabs; lung, kidneys, intestine (including contents), caecal tonsils, spleen, 
brain, liver and heart tissues, separately or as a pool 
 Live birds: tracheal or oropharyngeal and cloacael swabs (visibly coated with faecal material) 
from live birds or from pools of organs and faeces from dead birds 
o small delicate birds may be harmed by swabbing, but the collection of fresh faeces may 
serve as an adequate alternative 
 Special attention should be given to appropriate types of media for shipping 
Serological tests 
 Clotted blood samples or serum 
Procedures 
Identification of the agent 
 Virus isolation (the prescribed test for international trade): inoculation of embryonated specified 
pathogen free (SPF) eggs and tested for haemagglutination (HA) activity and/or by use of 
validated specific molecular methods 
 Virus identification: use of specific antiserum in a haemagglutination inhibition (HI) test 
o Cross-reactivity and the risk of mistyping an isolate can be greatly reduced by using a 
panel of reference sera or monoclonal antibodies (MAbs) specific for APMV-1, APMV-3, 
and APMV-7 
 Pathogenicity index determined by intracerebral methodology 
 Pathogenicity index determined by molecular basis 
 Definition of Newcastle disease; 
o a) criteria based on either intracerebral pathogenicity index (ICPI) in day-old chicks or 
o b) correlation of multiple basic amino acids 
 Monoclonal antibodies: for rapid identification of NDV (avoiding cross-reactions with other APMV 
serotypes) and a valuable method for grouping and differentiating isolates of NDV 
 Phylogenetic studies: allows for the rapid epidemiological assessment of the origins and spread 
of the viruses responsible for ND outbreaks 
 Molecular techniques in diagnosis: advantage of extremely rapid demonstration of the presence 
of virus 
Serological tests 
 Haemagglutination and haemagglutination inhibition tests: most widely used and detects antibody 
response to virus glycoprotein (predictor of protection against disease) 
 Enzyme-linked immunosorbent assay (ELISA): as whole virus is used as antigen, detects 
antibody to all of the virus proteins 
o commercial ELISA kits available to assess post-vaccination antibody levels 
For more detailed information regarding laboratory diagnostic methodologies, please refer to 
Chapter 2.3.14 Newcastle disease in the latest edition of the OIE Manual of Diagnostic Tests and 
Vaccines for Terrestrial Animals under the heading “Diagnostic Techniques”. 
PREVENTION AND CONTROL 
No treatment. 
Sanitary prophylaxis 
 Bird-proofing houses, feed and water supplies 
 Proper carcass disposal 
 Pest control in flocks; insects and mice 
 Avoidance of contact with birds of unknown health status; including newly acquired domesticated 
poultry, pet birds and wild or feral birds 
 Control of human traffic; facility employees should not have contact with outside birds and 
consideration of a policy of shower-in with dedicated clothing 
 Control of vehicular traffic; strict disinfection of conveyances and equipment 
 One age group per farm ('all in-all out') breeding is recommended; disinfection between groups 
 During outbreaks: 
o effective quarantines and movement controls 
o destruction of all infected and exposed birds; 21 days before restocking 
o thorough cleaning and disinfection of the premises 
Medical prophylaxis 
 One of the most important considerations for any vaccination programme is the type of vaccine to 
be used, the immune and disease status of the birds to be vaccinated, the level of maternal 
immunity in young chickens and the level of protection required in relation to any possibility of 
infection with field virus under local conditions; various strategies exist and references, like the 
OIE Terrestrial Manual, should be consulted 
 Vaccination with live and/or oil emulsion vaccines can markedly reduce the losses in poultry 
flocks but can not ensure the prevention of virus circulation (replication and shedding) 
 Sentinel chickens have been employed to monitor vaccinated flocks 
 In general, the more immunogenic live vaccines are more virulent, and are therefore more likely 
to cause adverse side-effects 
 Conventional live virus vaccines: 2 groups 
o lentogenic vaccines (e.g. Hitchner-B1, La Sota, V4, NDW, I2 and F) 
o mesogenic vaccines (e.g. Roakin, Mukteswar and Komarov); infections of these viruses 
would fall within the OIE definition of ND 
o live virus vaccines administered to birds by incorporation in the drinking water, delivered 
as a coarse spray (aerosol), or by intranasal or conjunctival instillation; some mesogenic 
strains are given by wing-web intradermal inoculation 
 Inactivated vaccines 
o tend to be more expensive than live vaccines 
o application entails handling and injecting individual birds 
o prepared from allantoic fluid that has had its infectivity inactivated by formaldehyde or 
beta-propiolactone 
o incorporated into an emulsion with mineral oil or vegetable oil, and is administered 
intramuscularly or subcutaneously; each bird thus receives a standard dose 
o advantage of no subsequent spread of virus or adverse respiratory reactions 
o virulent and avirulent strains are used as seed virus; from a safety control perspective 
the use of the latter appears more suitable 
o much larger amount of antigen is required for immunisation than for live virus vaccination 
(no virus multiplication takes place after administration) 
 New recombinant vaccines: fowlpox virus, vaccinia virus, pigeonpox virus, turkey herpesvirus and 
avian cells in which the HN gene, the F gene, or both, of NDV are expressed 
For more detailed information regarding vaccines, please refer to 2.3.14 Newcastle disease in the 
latest edition of the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals under the 
heading “Requirements for Vaccines”. 
For more detailed information regarding safe international trade in terrestrial animals and their 
products, please refer to the latest edition of the OIE Terrestrial Animal Health Code. 
REFERENCES AND OTHER INFORMATION 
 Brown C. & Torres A., Eds. (2008). - USAHA Foreign Animal Diseases, Seventh Edition. 
Committee of Foreign and Emerging Diseases of the US Animal Health Association. Boca 
Publications Group, Inc. 
 Coetzer J.A.W. & Tustin R.C. Eds. (2004). - Infectious Diseases of Livestock, 2nd Edition. Oxford 
University Press. 
 Fauquet C., Fauquet M. & Mayo M.A. (2005). - Virus Taxonomy: VIII Report of the International 
Committee on Taxonomy of Viruses. Academic Press. 
 Kahn C.M., Ed. (2005). - Merck Veterinary Manual. Merck & Co. Inc. and Merial Ltd. 
 SpicklerA.R. & Roth J.A. Iowa State University, College of Veterinary Medicine - 
http://www.cfsph.iastate.edu/DiseaseInfo/factsheets.htm 
 World Organisation for Animal Health (2012). - Terrestrial Animal Health Code. OIE, Paris. 
 World Organisation for Animal Health (2012). - Manual of Diagnostic Tests and Vaccines for 
Terrestrial Animals. OIE, Paris. 
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The OIE will periodically update the OIE Technical Disease Cards. Please send relevant new 
references and proposed modifications to the OIE Scientific and Technical Department 
(scientific.dept@oie.int). Last updated April 2013. 
mailto:scientific.dept@oie.int